From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66F891F3D5D for ; Fri, 27 Dec 2024 13:54:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735307644; cv=none; b=g083iPk/Ov7+0xcu0EoMNQKVdFK3QO1vvXwQUUAoIhkmHAYLb35WiqRaVPeQ4rqcJ13eh50xEeJxTic3/HBYbEUPeKvW1ddZx02tZrG8Ht+rZHjlZDY3g0nTwuxiYqVYLmxcwnRBhrYkj1W6sLKNvvQBP3YQ/LJhQ+KTg/IMh4Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735307644; c=relaxed/simple; bh=emmZhtwHPlGM2H6WcPtEb3DpZfUVdINMWjZuIxyUFD8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=CRBWwp4NAYxGKux2a3HkTzO0RhjZ9WQ6fO7KFaEFe/C3NhYehQrh4ZQmsguGLW0Mv60EyyWc+OePP+O9inpQXTwTVk+YKKjpRnq8Xw4Y5YiCKHRK1+83RgfRU/bmHnJmi7yOssF/O19CrbeajK9lG2BHzYtBNJ8qapRpPNdZ+AQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=X6DsNATk; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="X6DsNATk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DFD19C4CED0; Fri, 27 Dec 2024 13:54:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1735307644; bh=emmZhtwHPlGM2H6WcPtEb3DpZfUVdINMWjZuIxyUFD8=; h=From:To:Cc:Subject:Date:Reply-to:From; b=X6DsNATkkUAsToOq74UaZOEqzyA8tPyJc6tukxYj9rJQl1h1emQPkrzirzNyeR3zJ MquyvRFzndOn3ENbG1zEuKeaFL8V6IkusRrGLqqqs5GEth8ZXEDPRSVk+TQh9oRtS1 2QntXfp+Kmjj8Mr8GlexfD3WBpCPQao2IXPWI9Vo= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2024-53194: PCI: Fix use-after-free of slot->bus on hot remove Date: Fri, 27 Dec 2024 14:52:40 +0100 Message-ID: <2024122724-CVE-2024-53194-9edf@gregkh> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Reply-to: , X-Developer-Signature: v=1; a=openpgp-sha256; l=6246; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=emmZhtwHPlGM2H6WcPtEb3DpZfUVdINMWjZuIxyUFD8=; b=owGbwMvMwCRo6H6F97bub03G02pJDOl5GyWuXOJl9pdzFtT0s/5q6rumVOAfM2+zv+adCR/5m pnkXVo6YlkYBJkYZMUUWb5s4zm6v+KQopeh7WmYOaxMIEMYuDgFYCIu3QwL9lv9bj4euKfGfdt5 hqMXGPPERLXvMCxYnnb7j8j6UzNTvyosXzXrcL+p+aKDAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit Description =========== In the Linux kernel, the following vulnerability has been resolved: PCI: Fix use-after-free of slot->bus on hot remove Dennis reports a boot crash on recent Lenovo laptops with a USB4 dock. Since commit 0fc70886569c ("thunderbolt: Reset USB4 v2 host router") and commit 59a54c5f3dbd ("thunderbolt: Reset topology created by the boot firmware"), USB4 v2 and v1 Host Routers are reset on probe of the thunderbolt driver. The reset clears the Presence Detect State and Data Link Layer Link Active bits at the USB4 Host Router's Root Port and thus causes hot removal of the dock. The crash occurs when pciehp is unbound from one of the dock's Downstream Ports: pciehp creates a pci_slot on bind and destroys it on unbind. The pci_slot contains a pointer to the pci_bus below the Downstream Port, but a reference on that pci_bus is never acquired. The pci_bus is destroyed before the pci_slot, so a use-after-free ensues when pci_slot_release() accesses slot->bus. In principle this should not happen because pci_stop_bus_device() unbinds pciehp (and therefore destroys the pci_slot) before the pci_bus is destroyed by pci_remove_bus_device(). However the stacktrace provided by Dennis shows that pciehp is unbound from pci_remove_bus_device() instead of pci_stop_bus_device(). To understand the significance of this, one needs to know that the PCI core uses a two step process to remove a portion of the hierarchy: It first unbinds all drivers in the sub-hierarchy in pci_stop_bus_device() and then actually removes the devices in pci_remove_bus_device(). There is no precaution to prevent driver binding in-between pci_stop_bus_device() and pci_remove_bus_device(). In Dennis' case, it seems removal of the hierarchy by pciehp races with driver binding by pci_bus_add_devices(). pciehp is bound to the Downstream Port after pci_stop_bus_device() has run, so it is unbound by pci_remove_bus_device() instead of pci_stop_bus_device(). Because the pci_bus has already been destroyed at that point, accesses to it result in a use-after-free. One might conclude that driver binding needs to be prevented after pci_stop_bus_device() has run. However it seems risky that pci_slot points to pci_bus without holding a reference. Solely relying on correct ordering of driver unbind versus pci_bus destruction is certainly not defensive programming. If pci_slot has a need to access data in pci_bus, it ought to acquire a reference. Amend pci_create_slot() accordingly. Dennis reports that the crash is not reproducible with this change. Abridged stacktrace: pcieport 0000:00:07.0: PME: Signaling with IRQ 156 pcieport 0000:00:07.0: pciehp: Slot #12 AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surprise+ Interlock- NoCompl+ IbPresDis- LLActRep+ pci_bus 0000:20: dev 00, created physical slot 12 pcieport 0000:00:07.0: pciehp: Slot(12): Card not present ... pcieport 0000:21:02.0: pciehp: pcie_disable_notification: SLOTCTRL d8 write cmd 0 Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP NOPTI CPU: 13 UID: 0 PID: 134 Comm: irq/156-pciehp Not tainted 6.11.0-devel+ #1 RIP: 0010:dev_driver_string+0x12/0x40 pci_destroy_slot pciehp_remove pcie_port_remove_service device_release_driver_internal bus_remove_device device_del device_unregister remove_iter device_for_each_child pcie_portdrv_remove pci_device_remove device_release_driver_internal bus_remove_device device_del pci_remove_bus_device (recursive invocation) pci_remove_bus_device pciehp_unconfigure_device pciehp_disable_slot pciehp_handle_presence_or_link_change pciehp_ist The Linux kernel CVE team has assigned CVE-2024-53194 to this issue. Affected and fixed versions =========================== Fixed in 4.19.325 with commit 50473dd3b2a08601a078f852ea05572de9b1f86c Fixed in 5.4.287 with commit d0ddd2c92b75a19a37c887154223372b600fed37 Fixed in 5.10.231 with commit da6e6ff1f6c57f16e07af955e0e997fc90dd1e75 Fixed in 5.15.174 with commit 41bbb1eb996be1435815aa1fbcc9ffc45b84cc12 Fixed in 6.1.120 with commit 20502f0b3f3acd6bee300257556c27a867f80c8b Fixed in 6.6.64 with commit e5d5c04aac71bf1476dc44b56f2206a4c2facca8 Fixed in 6.11.11 with commit c8266ab8e7ccd1d1f5a9c8b29eb2020175048134 Fixed in 6.12.2 with commit 69d2ceac11acf8579d58d55c9c5b65fb658f916e Fixed in 6.13-rc1 with commit c7acef99642b763ba585f4a43af999fcdbcc3dc4 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2024-53194 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: drivers/pci/slot.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/50473dd3b2a08601a078f852ea05572de9b1f86c https://git.kernel.org/stable/c/d0ddd2c92b75a19a37c887154223372b600fed37 https://git.kernel.org/stable/c/da6e6ff1f6c57f16e07af955e0e997fc90dd1e75 https://git.kernel.org/stable/c/41bbb1eb996be1435815aa1fbcc9ffc45b84cc12 https://git.kernel.org/stable/c/20502f0b3f3acd6bee300257556c27a867f80c8b https://git.kernel.org/stable/c/e5d5c04aac71bf1476dc44b56f2206a4c2facca8 https://git.kernel.org/stable/c/c8266ab8e7ccd1d1f5a9c8b29eb2020175048134 https://git.kernel.org/stable/c/69d2ceac11acf8579d58d55c9c5b65fb658f916e https://git.kernel.org/stable/c/c7acef99642b763ba585f4a43af999fcdbcc3dc4